Radioactive waste has been buried in Vertical Pipe Units (VPU's) at various locations around the planet in many countries. The VPU's are hollow cylinders that are usually the length of five 55 gallon containers app. 15 feet long and 22 inches in diameter. In order to bury the VPU an excavation was prepared to the depth required and the VPU was set in the soil usually on a concrete footing or base. The VPU was then filled with smaller containers, such as vials and jars containing radio-active and non-radio active chemicals that may be liquid in nature. These VPU's are buried at known locations. The condition of the VPU's is unknown. Most of them were buried in the 1950's and corrosion could have damaged the steel walls of the VPU's. There is the present danger that after many years of burial the integrity of the VPU's is compromised such as these chemicals may leach out and contaminate the soil and get into the ground water. Presently an effective method to remediate and safely dispose of such waste does not exist. Remediation is the process of making a burial site non-toxic by the safe removal of the contents and back filling with fresh soil. Stabilization is the process of allowing the dangerous chemicals to react and mix with the soil thereby rendering them less dangerous to handle. In order to dispose of the waste buried in VPU's it is not safe to attempt to remove the buried VPU as a single unit because of the risk of leakage during removal. Furthermore, there is a need to have the capability of identifying the hazardous or non hazardous nature of the VPU contents because the method of disposal in each case will be different. The VPU contents get mixed with the surrounding soil. This process is completely contained within the enclosure provided by the apparatus used. The grinding of the VPU exposes the chemicals and allows chemical reactions to occur between the reactive chemicals stored in the VPU. This in-situ stabilization of contents makes it safer to remove and dispose. The chemical and soil mixture can be analyzed by various non destructive assay (NDA) methodologies and a continued determination made as to the hazardous nature of the mixed contents. This is determined by the measurement of radio activity to characterize the contents as to whether it is Transuranic (TRU) or not. U.S. Pat. No. 7,381,010 to Alexander et al 2008 Jun. 3 that showed a system and method of removal of buried objects did not resolve the stabilization and identification of the waste as shown in the embodiments described below. The aspects described below also addresses the in-situ stabilization of the hazardous contents that was not addressed by the Alexander patent.
The advantages listed below are for one or more aspects. The aspects discussed below efficiently render any VPU and its contents into a well mixed waste stream with no visible discrete objects (i.e anomalies) in a manner that is safe for workers; safe for the environment, meets applicable environmental regulations and does not expose identifiable waste objects to the atmosphere. Furthermore, the waste is efficiently removed from the waste site. It is characterized with respect to transuranic (TRU) isotope concentration. Waste is characterized with respect to waste acceptance criteria. Specially designated waste disposal facilities exist in the USA for TRU waste and non TRU waste.
Thus several advantages of one or more aspects are that the containers are punctured and the waste mixed with the soil. This technique allows the chemicals contained in the waste to react with each other thereby reducing the reactivity of the chemicals. The waste is mixed with the soil and in one or more aspects in situ measurement of radiation is done to characterize the waste in terms of its radioactivity. This process of grinding of the contents of the VPU with the soil leads to stabilization of the waste. A NDA is conducted in-situ to categorize the radioactivity of the waste. Optical inspection of the waste in one aspect provides a visual record of the stabilized waste prior to disposal. The aspects also show the system and safe removal of the waste/soil mixture depending on the category of the mixture based on its radioactive level without danger of emission or leakage into the environment. The mixing with the soil allows the liquids to be absorbed and the waste will not have free liquids that are prohibited to be present in the waste regardless of whether they are radioactive or non hazardous liquids. These and other advantages of one or more aspects will become apparent from consideration of the ensuing description and accompanying drawings.